BPC-157 reconstitution: which diluent, how much, why
BPC-157 ships as a lyophilized powder in a sealed vial — typically 5 mg per vial. The choice of diluent and the volume you add determine shelf-life (days to weeks), sterility, and the per-dose volume on the syringe. Get it wrong and either the vial spoils early or your doses are out of spec.
Diluent: BAC water vs sterile saline
| Diluent | Composition | Antimicrobial | Max in-use shelf life | Best for |
|---|---|---|---|---|
| BAC water | Sterile water + 0.9% benzyl alcohol | Yes — suppresses growth | 28–30 days refrigerated | Multi-dose vials |
| Sterile saline (0.9%) | Sterile water + 0.9% NaCl | None | 24 hours refrigerated | Single-use only |
| Sterile water (USP) | Plain sterile water, no preservative | None | 24 hours refrigerated | Single-use only |
| Tap water / distilled water | Non-sterile | None | Do not use | — |
Default to BAC water for almost all peptide reconstitution. The benzyl alcohol preservative is what allows 28-day intermittent multi-dose use without infection risk. The few exceptions:
- Benzyl alcohol allergy or sensitivity. Switch to sterile saline and treat each vial as single-use.
- Neonates. Benzyl alcohol is contraindicated. Not a relevant case for typical research-use BPC-157 work.
- BAC-incompatible peptides. Some peptides (rare for BPC-157) are degraded by benzyl alcohol. Check the COA notes.
How much diluent to add
The volume of diluent controls concentration and per-dose draw size. Standard reconstitutions for a 5 mg BPC-157 vial:
| BAC water added | Concentration | 250 mcg dose | 500 mcg dose | Use case |
|---|---|---|---|---|
| 2 mL | 2.5 mg/mL | 0.10 mL (10 U) | 0.20 mL (20 U) | Standard — comfortable draw size |
| 2.5 mL | 2 mg/mL | 0.125 mL (12.5 U) | 0.25 mL (25 U) | Cleaner math for 125 mcg increments |
| 5 mL | 1 mg/mL | 0.25 mL (25 U) | 0.50 mL (50 U) | Less concentrated; longer in-use clock matters less |
| 1 mL | 5 mg/mL | 0.05 mL (5 U) | 0.10 mL (10 U) | Tighter math; less margin for syringe error |
The 2.5 mg/mL setup is the most common and balances reasonable draw volume (easy to measure 10–20 U on a syringe) with concentration low enough that small dose errors aren't catastrophic.
Reconstitution technique
- Cold start. Bring both vials to room temperature before opening. Cold vials condense water and have higher syringe-aspiration resistance.
- Wipe both stoppers with 70% isopropyl alcohol; let dry.
- Draw the diluent into a syringe — use a needle one gauge larger than your injection needle to reduce shear during the next step.
- Inject the diluent slowly down the side wall of the peptide vial, not directly onto the powder. Direct stream on the powder can foam the peptide and cause aggregation.
- Do not shake. Swirl gently or let it sit for 5 minutes. Shaking causes shear-aggregation.
- Inspect. The solution should be clear, colorless, like water. Cloudiness or particulates → discard. See why BPC-157 turns cloudy.
- Label and refrigerate. Date of reconstitution, concentration, expiry (28 days from reconstitution).
Per-dose draw math
For 5 mg + 2 mL BAC water = 2.5 mg/mL:
Example: 250 mcg × 0.04 = 10 U.
Storage and in-use life
- Refrigerator, 2–8 °C, in original vial, away from light.
- 28-day clock from reconstitution. Discard at day 29 regardless of remaining volume.
- Don't freeze. See why freezing peptides is irreversible.
- Alcohol-wipe the stopper before every draw. Each puncture is an infection risk; BAC water suppresses but doesn't prevent it indefinitely.
FAQ
Why not just add 1 mL for a higher concentration?
You can, and it works — but draw volumes shrink to 5 units or less, where syringe accuracy is at its worst. The 2 mL / 2.5 mg/mL setup is the practical sweet spot.
Can I use the same vial for two reconstitutions if I run out of solution before 28 days?
Yes. Reconstitution of a multi-dose vial doesn't reset the 28-day clock — but the clock starts at first reconstitution, so a vial used down to empty within 28 days is fine. If you reconstitute a fresh vial, that's a new 28-day clock.
Does the BAC water need to be fresh?
BAC water is stable at room temperature for at least 12 months if the seal is intact. Once opened (stopper punctured), use within 28 days same as the reconstituted peptide.
What if the vial powder doesn't look like a clean cake?
BPC-157 lyophilized powder ranges from a fluffy white cake to a barely-visible film at the bottom of the vial. Both are normal. A discolored powder (yellow, brown) is a quality issue — contact the supplier.
Related reading
Time every vial from reconstitution
Peptide Protocol records your reconstitution date for each vial and warns you 5 days before the 28-day shelf life expires.
Get the iPhone app →Informational and educational only. Not medical advice. Consult a licensed clinician before starting, changing, or stopping any peptide protocol. Mentions of investigational, compounded, or research-use peptides are for informational purposes; many such substances are not FDA-approved for human use.